Scientists propose new method to correct common power problem in microgrids

June 7, 2017

Scientists from the Northeastern University, China, have developed a new method to diagnose a serious electrical problem in microgrids. They have published their work in IEEE/CAA Journal of Automatica Sinica (JAS), a joint publication of the Institute of Electrical and Electronic Engineers (IEEE) and the Chinese Association of Automation.

Microgrids are island-like pods of generation with bridges to the main power grid. If power supplied by the main grid is disrupted, the microgrid can disconnect and continuing supplying power locally.

"In response to societal requirements, [the] microgrid system has received considerable attention," write Prof. Zhanshan Wang and Prof. Huaguang Zhang. "The reliability of the inverter is considered an important factor to guarantee the high quality, continuousness, and safe operation of the microgrid."

The inverter takes the direct current supplied by the main grid and converts it to alternating current, which household electronics use. Power flows through the circuit from the source to a computer or coffeemaker. When the appliance is no longer needed, a interrupts the circuit, rerouting the current to wherever else it's needed. But sometimes the switch sticks, and the current continues to flow.

"[An open-switch fault] often affects the normal operation of the entire drive system and has many serious influences," says Wang. "For example, [it can cause]... overcurrent stress to other power switches or electronic components... low efficiency; [and] high repair costs."

The switch can be flipped back and the problem corrected—if grid managers know there's a fault and where it is. A switch fault, which can cause an electrical fire, may not be obvious until the fallout becomes obvious. With so many switches throughout the microgrid system, it's nearly impossible to determine which one is at fault.

That's the problem this research team set out to solve. They developed an algorithm to accurately identify multiple signals at multiple levels in the circuit, which can determine if a switch fault exists. The location of the faulty signals is identified through an artificial neural network—a series of connected computers that learns to process information based on the information itself.

The combination of the algorithm and the neural network can detect and identify the exact open-switch , according to the researchers. Since the detection and identification occurs simultaneously, the scientists also say that their method can improve the reliability, efficiency and cost of the .

Explore further: New innovation in modeling and designing power grids

More information: Zhanjun Huang et al, Multilevel feature moving average ratio method for fault diagnosis of the microgrid inverter switch, IEEE/CAA Journal of Automatica Sinica (2017). DOI: 10.1109/JAS.2017.7510496

Related Stories

New innovation in modeling and designing power grids

October 20, 2016

You can teach an old dog new tricks—this seems to be true for the research group led by Mengchu Zhou, a distinguished professor of electrical and computer engineering at the New Jersey Institute of Technology. In a recent ...

Going off-grid easier with friends

April 25, 2016

With WA's power grid ageing and energy bills soaring, microgrids have never been more talked about—and they're easier with friends.

Chinese researchers develop algorithms for smart energy grid

October 20, 2016

A fallen tree, a lightning strike—it doesn't take much to disrupt the electrical grid. An outage could last just a few minutes, but restoring electricity to millions of people typically takes hours, days or even weeks. ...

Going back in time to locate short circuits in power grids

November 10, 2015

EPFL researchers have come up with a method to determine the exact location of short circuits in a power grid. This is an important step towards operating complex power grid topologies that enable the massive integration ...

Recommended for you

US faces moment of truth on 'net neutrality'

December 14, 2017

The acrimonious battle over "net neutrality" in America comes to a head Thursday with a US agency set to vote to roll back rules enacted two years earlier aimed at preventing a "two-speed" internet.

FCC votes along party lines to end 'net neutrality' (Update)

December 14, 2017

The Federal Communications Commission repealed the Obama-era "net neutrality" rules Thursday, giving internet service providers like Verizon, Comcast and AT&T a free hand to slow or block websites and apps as they see fit ...

The wet road to fast and stable batteries

December 14, 2017

An international team of scientists—including several researchers from the U.S. Department of Energy's (DOE) Argonne National Laboratory—has discovered an anode battery material with superfast charging and stable operation ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.